mm: show migration types in show_mem
This is useful to diagnose the reason for page allocation failure for cases where there appear to be several free pages. Example, with this alloc_pages(GFP_ATOMIC) failure: swapper/0: page allocation failure: order:0, mode:0x0 ... Mem-info: Normal per-cpu: CPU 0: hi: 90, btch: 15 usd: 48 CPU 1: hi: 90, btch: 15 usd: 21 active_anon:0 inactive_anon:0 isolated_anon:0 active_file:0 inactive_file:84 isolated_file:0 unevictable:0 dirty:0 writeback:0 unstable:0 free:4026 slab_reclaimable:75 slab_unreclaimable:484 mapped:0 shmem:0 pagetables:0 bounce:0 Normal free:16104kB min:2296kB low:2868kB high:3444kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:336kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:331776kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:300kB slab_unreclaimable:1936kB kernel_stack:328kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 Before the patch, it's hard (for me, at least) to say why all these free chunks weren't considered for allocation: Normal: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 1*256kB 1*512kB 1*1024kB 1*2048kB 3*4096kB = 16128kB After the patch, it's obvious that the reason is that all of these are in the MIGRATE_CMA (C) freelist: Normal: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 1*256kB (C) 1*512kB (C) 1*1024kB (C) 1*2048kB (C) 3*4096kB (C) = 16128kB Signed-off-by: NRabin Vincent <rabin.vincent@stericsson.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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